THE CONDITION OF MENTAL FACULTIES - the indications derived from this source may be referred to two principal heads—consciousness and coherence—perception and reflection. These correspond to two very clearly defined features of disease expressed by the terms coma and delirium.
Between the two extremes we find an almost endless variety of examples, in which they are, more or less, blended together, where it is scarcely possible to tell whether the perceptive or the reflec tive powers be most in abeyance; in such instances there is partial loss of consciousness, with a certain amount of insensibility to ordinary stimulus, and confusion of thought, without active deli rium; they may be only the transition stage from one state to the other, but are often distinct from either. Coma is related to sleep, of which it presents the greatest possible exaggeration; while delirium is associated with insomnia, which is its invariable attendant, and often appears as its precursor.
§ 1. Coma, or Insensibility.—Consciousness is entir us pended ; the mind is a perfect blank-I–the p-atiaris e deprived of the power of tlaQught, _ancLexpresiio.n, an_ ,f:1 of the knowledfre Iternal things; voluntary action has altocer e , . . _ o.
Takes no reply to any question ; he may be pinched or puffer ab6ut, and he gives no evidence of pain or annoyance ; the mus cular movements are only fhose of organic life, or such as may be excited by a sort of reflex action, or unconscious resistance. In such cases it is important to discover whether the absence of volunta.ry action depends merely on the state of coma, or whether there be distinct paralysis of some of the muscles • a limb placed in a constrained position is moved in the one case 7by the counter poise of flexion and extension, in the other it remains a.s a lifeless object in a condition of rest. When paralysis is present, the extent of the lesion is measured in some degree by the number and variety of the parts implicated; but two conditions are chiefly observed—hemiplegia, affecting one entire lateral half of the body; paraplegia, or general paralysis, invoking both sides alike. (See Div. III., § 2, of this chapter.) If any history can be obtained, we have to inquire how the patient passed into his present state, whether he was attacked suddenly, or gradually increasing stupor and somnolence preceded the coma; and in the former case, if there were any convulsive movement in the first onset of the attack. When no one was
present to observe these circumstances, we may still learn much from the position in which the patient was found; as it point's to the seizure having occurred when he was at rest, or having given him warning of its approach, or to its having overtaken him in the midst of action or exertion, or to its being the possible result of accidental injury.
This condition is found in several different states. a. It may be the result of a fall or a blow, when extravasation has been caused by fracture of the skull. The coma of concussion, which is the first effect of the accident, is not so deep, and there is never paralysis ; hemiplegia points especially to ex travasation. In their further progress these cases may pass into inflammation and serious disorganization of the brain.
b. An apoplectic seizure, in which the patient has suddenly.fallen down in sensible, without convulsion, or with convulsive res oo marked. When hemiplegia coexists with coma, without any trace of injury, the diagnosis is cert rA C may exist without paralysis, and then its presen, negatively, by the exclusion of other possible taus c. A comatose state may be caused by intoxical of these does it come on so rapidly ; intoxication of the breath ; and in poisoning by opium the called to some degree of consciousness, until neap cases the previous circumstances, and the positi found, may be of great service in guiding our opinion.
d. Coma may also be the result of extensive effusion of serum into the ventricles of the brain. It is difficult to conceive how this can happen sud denly, and yet it is quite certain that patients are seized while walking along the street, or engaged in their usual avocations, with a fit, generally more or less convulsive in character, followed by coma, and not unfrequently attended with either paralysis or continued spasmodic action of one side of the body. The diagnosis rests chiefly on two points, the existence of convulsions in the primary seizure, and the extent of the coma which is scarcely so complete as in apoplexy ; in the latter spasmodic movements are seldom met with. A history of previous bad health, with debility, would lead to the suspicion of effusion; a florid face and a full habit point more generally to sanguineous apoplexy.